From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751811AbdK3IdH (ORCPT ); Thu, 30 Nov 2017 03:33:07 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:56664 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750943AbdK3IdG (ORCPT ); Thu, 30 Nov 2017 03:33:06 -0500 From: Ravi Bangoria To: mpe@ellerman.id.au Cc: benh@kernel.crashing.org, paulus@samba.org, maddy@linux.vnet.ibm.com, tglx@linutronix.de, kan.liang@intel.com, sukadev@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Ravi Bangoria Subject: [PATCH] powerpc/perf: Fix oops when grouping different pmu events Date: Thu, 30 Nov 2017 14:03:22 +0530 X-Mailer: git-send-email 2.13.6 X-TM-AS-GCONF: 00 x-cbid: 17113008-0040-0000-0000-000004144890 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17113008-0041-0000-0000-000020B72F60 Message-Id: <20171130083322.31206-1-ravi.bangoria@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-11-30_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1711300114 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When user tries to group imc (In-Memory Collections) event with normal event, (sometime) kernel crashes with following log: Faulting instruction address: 0x00000000 [link register ] c00000000010ce88 power_check_constraints+0x128/0x980 ... c00000000010e238 power_pmu_event_init+0x268/0x6f0 c0000000002dc60c perf_try_init_event+0xdc/0x1a0 c0000000002dce88 perf_event_alloc+0x7b8/0xac0 c0000000002e92e0 SyS_perf_event_open+0x530/0xda0 c00000000000b004 system_call+0x38/0xe0 'event_base' field of 'struct hw_perf_event' is used as flags for normal hw events and used as memory address for imc events. While grouping these two types of events, collect_events() tries to interpret imc 'event_base' as a flag, which causes a corruption resulting in a crash. Consider only those events which belongs to 'perf_hw_context' in collect_events(). Signed-off-by: Ravi Bangoria --- arch/powerpc/perf/core-book3s.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 9e3da16..1538129 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1415,7 +1415,7 @@ static int collect_events(struct perf_event *group, int max_count, int n = 0; struct perf_event *event; - if (!is_software_event(group)) { + if (group->pmu->task_ctx_nr == perf_hw_context) { if (n >= max_count) return -1; ctrs[n] = group; @@ -1423,7 +1423,7 @@ static int collect_events(struct perf_event *group, int max_count, events[n++] = group->hw.config; } list_for_each_entry(event, &group->sibling_list, group_entry) { - if (!is_software_event(event) && + if (event->pmu->task_ctx_nr == perf_hw_context && event->state != PERF_EVENT_STATE_OFF) { if (n >= max_count) return -1; -- 1.8.3.1