From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751640Ab3A1Fe7 (ORCPT ); Mon, 28 Jan 2013 00:34:59 -0500 Received: from mga02.intel.com ([134.134.136.20]:12695 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114Ab3A1Fe5 (ORCPT ); Mon, 28 Jan 2013 00:34:57 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,548,1355126400"; d="scan'208";a="277315685" Subject: [PATCH] perf: Add the rcu_read_lock to protect the list_for_each_entry_rcu. From: Jun Chen To: a.p.zijlstra@chello.nl, paulus@samba.org, mingo@redhat.com, acme@ghostprotocols.net Cc: Linux Kernel , Jun Chen Content-Type: text/plain; charset="UTF-8" Date: Mon, 28 Jan 2013 08:36:28 -0500 Message-ID: <1359380188.8410.11.camel@chenjun-workstation> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The list_for_each_entry_rcu should be guarded by rcu_read_lock().This patch add rcu_read_lock to protect the list_for_each_entry_rcu. Signed-off-by: Chen Jun --- kernel/events/core.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 301079d..e2f2fa5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2442,6 +2442,7 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, raw_spin_lock(&ctx->lock); perf_pmu_disable(ctx->pmu); + rcu_read_lock(); list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { if (event->state != PERF_EVENT_STATE_ACTIVE) @@ -2483,6 +2484,7 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); } + rcu_read_unlock(); perf_pmu_enable(ctx->pmu); raw_spin_unlock(&ctx->lock); } -- 1.7.4.1