From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11D07C33CB1 for ; Wed, 15 Jan 2020 10:59:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E34E924671 for ; Wed, 15 Jan 2020 10:59:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729828AbgAOK7W (ORCPT ); Wed, 15 Jan 2020 05:59:22 -0500 Received: from foss.arm.com ([217.140.110.172]:34942 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726550AbgAOK7V (ORCPT ); Wed, 15 Jan 2020 05:59:21 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 58AA51007; Wed, 15 Jan 2020 02:59:21 -0800 (PST) Received: from e112479-lin.warwick.arm.com (e112479-lin.warwick.arm.com [10.32.36.146]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 34A4C3F6C4; Wed, 15 Jan 2020 02:59:18 -0800 (PST) From: James Clark To: linux-arm-kernel@lists.infradead.org Cc: nd@arm.com, James Clark , Will Deacon , Mark Rutland , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Tan Xiaojun , Al Grant , Namhyung Kim , linux-kernel@vger.kernel.org Subject: [PATCH 1/1] Return EINVAL when precise_ip perf events are requested on Arm Date: Wed, 15 Jan 2020 10:58:55 +0000 Message-Id: <20200115105855.13395-2-james.clark@arm.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20200115105855.13395-1-james.clark@arm.com> References: <20200115105855.13395-1-james.clark@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ARM PMU events can be delivered with arbitrary skid, and there's nothing the kernel can do to prevent this. Given that, the PMU cannot support precise_ip != 0. Also update comment to state that attr.config field is used to set the event type rather than event_id which doesn't exist. Signed-off-by: James Clark Cc: Will Deacon Cc: Mark Rutland Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Tan Xiaojun Cc: Al Grant Cc: Namhyung Kim Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org --- drivers/perf/arm_pmu.c | 3 +++ include/uapi/linux/perf_event.h | 4 ++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index df352b334ea7..4ddbdb93b3b6 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -102,6 +102,9 @@ armpmu_map_event(struct perf_event *event, u64 config = event->attr.config; int type = event->attr.type; + if (event->attr.precise) + return -EINVAL; + if (type == event->pmu->type) return armpmu_map_raw_event(raw_event_mask, config); diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 377d794d3105..3501b2eb168a 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -38,8 +38,8 @@ enum perf_type_id { }; /* - * Generalized performance event event_id types, used by the - * attr.event_id parameter of the sys_perf_event_open() + * Generalized hardware performance event types, used by the + * attr.config parameter of the sys_perf_event_open() * syscall: */ enum perf_hw_id { -- 2.24.0