From patchwork Tue Sep 1 15:10:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 264666 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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 08255C433E2 for ; Tue, 1 Sep 2020 15:57:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6BC1206EB for ; Tue, 1 Sep 2020 15:57:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598975835; bh=jQ+lvqk8m21u94r+IH23YkPMdq4xCdiRLIOoDC8ASpw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=s6n3DObDpvaBYU/Zi2o9NfEJacZSGh/yKHVBrRh/iNciGPuzy7Th5q2qia9415yLU KT9FdVCTVGQEzYB3NU2zU9o+7HNSMMTPtn5IjUZcmRIp44/cdpM6IPwEJIRj+kYXu0 PaMo3DAJUq3272V7q/ER/ZEvGfgTp+Ua5KxPDPHc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731296AbgIAP5H (ORCPT ); Tue, 1 Sep 2020 11:57:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:60402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731793AbgIAPon (ORCPT ); Tue, 1 Sep 2020 11:44:43 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B7464206EB; Tue, 1 Sep 2020 15:44:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598975082; bh=jQ+lvqk8m21u94r+IH23YkPMdq4xCdiRLIOoDC8ASpw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RkT4ryxyHhP0md8Ob6jP7ZEKbiOiUQyR10BQ4INfYVdHoTTuKmEZBv0UQv0tNU5X5 Lr6P4vRfcTBpTNA/eJ9vHNB2fXtw9ONn3gcUAkWtC12OlSbq68evGZ12I8QG3NsQzT qmTplpk75/yjU18ONJgyKwmgW5l5rrtqpAVI46lk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexey Kardashevskiy , Madhavan Srinivasan , Michael Ellerman Subject: [PATCH 5.8 202/255] powerpc/perf: Fix crashes with generic_compat_pmu & BHRB Date: Tue, 1 Sep 2020 17:10:58 +0200 Message-Id: <20200901151010.375799862@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901151000.800754757@linuxfoundation.org> References: <20200901151000.800754757@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexey Kardashevskiy commit b460b512417ae9c8b51a3bdcc09020cd6c60ff69 upstream. The bhrb_filter_map ("The Branch History Rolling Buffer") callback is only defined in raw CPUs' power_pmu structs. The "architected" CPUs use generic_compat_pmu, which does not have this callback, and crashes occur if a user tries to enable branch stack for an event. This add a NULL pointer check for bhrb_filter_map() which behaves as if the callback returned an error. This does not add the same check for config_bhrb() as the only caller checks for cpuhw->bhrb_users which remains zero if bhrb_filter_map==0. Fixes: be80e758d0c2 ("powerpc/perf: Add generic compat mode pmu driver") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Alexey Kardashevskiy Reviewed-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200602025612.62707-1-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/perf/core-book3s.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1517,9 +1517,16 @@ nocheck: ret = 0; out: if (has_branch_stack(event)) { - power_pmu_bhrb_enable(event); - cpuhw->bhrb_filter = ppmu->bhrb_filter_map( - event->attr.branch_sample_type); + u64 bhrb_filter = -1; + + if (ppmu->bhrb_filter_map) + bhrb_filter = ppmu->bhrb_filter_map( + event->attr.branch_sample_type); + + if (bhrb_filter != -1) { + cpuhw->bhrb_filter = bhrb_filter; + power_pmu_bhrb_enable(event); + } } perf_pmu_enable(event->pmu); @@ -1841,7 +1848,6 @@ static int power_pmu_event_init(struct p int n; int err; struct cpu_hw_events *cpuhw; - u64 bhrb_filter; if (!ppmu) return -ENOENT; @@ -1947,7 +1953,10 @@ static int power_pmu_event_init(struct p err = power_check_constraints(cpuhw, events, cflags, n + 1); if (has_branch_stack(event)) { - bhrb_filter = ppmu->bhrb_filter_map( + u64 bhrb_filter = -1; + + if (ppmu->bhrb_filter_map) + bhrb_filter = ppmu->bhrb_filter_map( event->attr.branch_sample_type); if (bhrb_filter == -1) {