From patchwork Mon Nov 23 09:49:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Athira Rajeev X-Patchwork-Id: 1404704 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Cfj9x3tTDz9sVD for ; Mon, 23 Nov 2020 20:52:21 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=drFWZTjV; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4Cfj9x0FTYzDqND for ; Mon, 23 Nov 2020 20:52:21 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=atrajeev@linux.vnet.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256 header.s=pp1 header.b=drFWZTjV; dkim-atps=neutral Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Cfj7g0ft5zDqM6 for ; Mon, 23 Nov 2020 20:50:22 +1100 (AEDT) Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0AN9WASu058889; Mon, 23 Nov 2020 04:50:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=pp1; bh=Nd2ABCwUYOztSs51lybEVHnA8qLHo3M2gRyfQGSjr6Q=; b=drFWZTjVW4gGvlqaULzgPJfq108lcaGLDPLN89fLcmOgpZXP4/8ZIz5VY0xSNeD5pXJv NAs+oYAxROGk1r1W+4ZJ55CJG1HEUdxJGGbH03TweZitpivCqjLsAfxZdcVQIdg2yn69 2zZP1vnyuh7qWWvtv0LdxC7IqFSKWWeCsuJKgJTaWWJYV/+70QdpYICYfvdsTEg1dkgP bsi9yWPnm2O/F9lpqkfAZp0hQSYnBCoI1E+pEcYv7f3EvFslUrpht70t8JOjd1gCLQv2 o2HWniBk6PimotwiqMaRzkZ+vLlMF13SAp09QYoyb02ieG4O7fQwHOkOVgMJSrOmiVx4 PA== Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 34yghqvam6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 23 Nov 2020 04:50:14 -0500 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0AN9XuOD015427; Mon, 23 Nov 2020 09:50:03 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma03fra.de.ibm.com with ESMTP id 34yy8r0ata-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 23 Nov 2020 09:50:03 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0AN9o1cU64815384 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 23 Nov 2020 09:50:01 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 213EE4C040; Mon, 23 Nov 2020 09:50:01 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D16AE4C050; Mon, 23 Nov 2020 09:49:59 +0000 (GMT) Received: from localhost.localdomain.localdomain (unknown [9.79.228.11]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 23 Nov 2020 09:49:59 +0000 (GMT) From: Athira Rajeev To: mpe@ellerman.id.au Subject: [PATCH] powerpc/perf: Fix crash with 'is_sier_available' when pmu is not set Date: Mon, 23 Nov 2020 04:49:57 -0500 Message-Id: <1606124997-3358-1-git-send-email-atrajeev@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312, 18.0.737 definitions=2020-11-23_02:2020-11-20, 2020-11-23 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 suspectscore=1 bulkscore=0 spamscore=0 priorityscore=1501 lowpriorityscore=0 impostorscore=0 malwarescore=0 clxscore=1015 phishscore=0 adultscore=0 mlxlogscore=817 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011230064 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: sachinp@linux.vnet.ibm.com, maddy@linux.ibm.com, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" On systems without any platform specific PMU driver support registered or Generic Compat PMU support registered, running 'perf record' with —intr-regs will crash ( perf record -I ). The relevant portion from crash logs and Call Trace: Unable to handle kernel paging request for data at address 0x00000068 Faulting instruction address: 0xc00000000013eb18 Oops: Kernel access of bad area, sig: 11 [#1] CPU: 2 PID: 13435 Comm: kill Kdump: loaded Not tainted 4.18.0-193.el8.ppc64le #1 NIP: c00000000013eb18 LR: c000000000139f2c CTR: c000000000393d80 REGS: c0000004a07ab4f0 TRAP: 0300 Not tainted (4.18.0-193.el8.ppc64le) NIP [c00000000013eb18] is_sier_available+0x18/0x30 LR [c000000000139f2c] perf_reg_value+0x6c/0xb0 Call Trace: [c0000004a07ab770] [c0000004a07ab7c8] 0xc0000004a07ab7c8 (unreliable) [c0000004a07ab7a0] [c0000000003aa77c] perf_output_sample+0x60c/0xac0 [c0000004a07ab840] [c0000000003ab3f0] perf_event_output_forward+0x70/0xb0 [c0000004a07ab8c0] [c00000000039e208] __perf_event_overflow+0x88/0x1a0 [c0000004a07ab910] [c00000000039e42c] perf_swevent_hrtimer+0x10c/0x1d0 [c0000004a07abc50] [c000000000228b9c] __hrtimer_run_queues+0x17c/0x480 [c0000004a07abcf0] [c00000000022aaf4] hrtimer_interrupt+0x144/0x520 [c0000004a07abdd0] [c00000000002a864] timer_interrupt+0x104/0x2f0 [c0000004a07abe30] [c0000000000091c4] decrementer_common+0x114/0x120 When perf record session started with "-I" option, capture registers via intr-regs, on each sample ‘is_sier_available()'i is called to check for the SIER ( Sample Instruction Event Register) availability in the platform. This function in core-book3s access 'ppmu->flags'. If platform specific pmu driver is not registered, ppmu is set to null and accessing its members results in crash. Patch fixes this by returning false in 'is_sier_available()' if 'ppmu' is not set. Fixes: 333804dc3b7a ("powerpc/perf: Update perf_regs structure to include SIER") Reported-by: Sachin Sant Signed-off-by: Athira Rajeev Tested-by: Sachin Sant --- arch/powerpc/perf/core-book3s.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 08643cb..1de4770 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -137,6 +137,9 @@ static void pmao_restore_workaround(bool ebb) { } bool is_sier_available(void) { + if (!ppmu) + return false; + if (ppmu->flags & PPMU_HAS_SIER) return true;