From patchwork Fri Aug 12 16:25:53 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pawel Moll X-Patchwork-Id: 9277403 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0646E60780 for ; Fri, 12 Aug 2016 16:28:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA82128AA2 for ; Fri, 12 Aug 2016 16:28:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DE5F028AA4; Fri, 12 Aug 2016 16:28:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 78FC028AA2 for ; Fri, 12 Aug 2016 16:28:09 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bYFI7-0004WA-DP; Fri, 12 Aug 2016 16:26:39 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bYFHp-0004Ns-EB for linux-arm-kernel@lists.infradead.org; Fri, 12 Aug 2016 16:26:22 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 97DF63ED; Fri, 12 Aug 2016 09:27:31 -0700 (PDT) Received: from hornet.cambridge.arm.com (hornet.cambridge.arm.com [10.2.206.194]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 57EDC3F213; Fri, 12 Aug 2016 09:26:01 -0700 (PDT) From: Pawel Moll To: arm@kernel.org Subject: [PATCH 2/5] bus: arm-ccn: Do not attempt to configure XPs for cycle counter Date: Fri, 12 Aug 2016 17:25:53 +0100 Message-Id: <1471019156-5485-3-git-send-email-pawel.moll@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1471019156-5485-1-git-send-email-pawel.moll@arm.com> References: <1471019156-5485-1-git-send-email-pawel.moll@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160812_092621_551101_D26C7996 X-CRM114-Status: UNSURE ( 8.31 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Fuzzing the CCN perf driver revealed a small but definitely dangerous mistake in the event setup code. When a cycle counter is requested, the driver should not reconfigure the events bus at all, otherwise it will corrupt (in most but the simplest cases) its configuration and may end up accessing XP array out of its bounds. Reported-by: Mark Rutland Reviewed-by: Mark Rutland Tested-by: Mark Rutland Cc: stable@vger.kernel.org # 3.17+ Signed-off-by: Pawel Moll --- drivers/bus/arm-ccn.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index a11b9bb..9bbb0ab 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -897,6 +897,10 @@ static void arm_ccn_pmu_xp_dt_config(struct perf_event *event, int enable) struct arm_ccn_component *xp; u32 val, dt_cfg; + /* Nothing to do for cycle counter */ + if (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER) + return; + if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP) xp = &ccn->xp[CCN_CONFIG_XP(event->attr.config)]; else